From e8e2f92b1553b977aef8bb4fa4e4c5b69c8d9d54 Mon Sep 17 00:00:00 2001 From: Vaishnav Achath Date: Wed, 14 Sep 2022 16:30:49 +0530 Subject: [PATCH] dmaengine: ti: k3-udma: Respond TX done if DMA_PREP_INTERRUPT is not requested If the DMA consumer driver does not expect the callback for TX done, then we need not perform the channel RT byte counter calculations and estimate the completion but return complete on first attempt itself.This assumes that the consumer who did not request DMA_PREP_INTERRUPT has its own mechanism for understanding TX completion, example: MCSPI EOW interrupt can be used as TX completion signal for a SPI transaction. Signed-off-by: Vaishnav Achath Acked-by: Peter Ujfalusi Link: https://lore.kernel.org/r/20220914110049.5842-1-vaishnav.a@ti.com Signed-off-by: Vinod Koul --- drivers/dma/ti/k3-udma.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/drivers/dma/ti/k3-udma.c b/drivers/dma/ti/k3-udma.c index fcfcde947b30..7b5081989b3d 100644 --- a/drivers/dma/ti/k3-udma.c +++ b/drivers/dma/ti/k3-udma.c @@ -263,6 +263,7 @@ struct udma_chan_config { enum udma_tp_level channel_tpl; /* Channel Throughput Level */ u32 tr_trigger_type; + unsigned long tx_flags; /* PKDMA mapped channel */ int mapped_channel_id; @@ -1055,9 +1056,14 @@ static bool udma_is_desc_really_done(struct udma_chan *uc, struct udma_desc *d) { u32 peer_bcnt, bcnt; - /* Only TX towards PDMA is affected */ + /* + * Only TX towards PDMA is affected. + * If DMA_PREP_INTERRUPT is not set by consumer then skip the transfer + * completion calculation, consumer must ensure that there is no stale + * data in DMA fabric in this case. + */ if (uc->config.ep_type == PSIL_EP_NATIVE || - uc->config.dir != DMA_MEM_TO_DEV) + uc->config.dir != DMA_MEM_TO_DEV || !(uc->config.tx_flags & DMA_PREP_INTERRUPT)) return true; peer_bcnt = udma_tchanrt_read(uc, UDMA_CHAN_RT_PEER_BCNT_REG); @@ -3418,6 +3424,8 @@ udma_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl, if (!burst) burst = 1; + uc->config.tx_flags = tx_flags; + if (uc->config.pkt_mode) d = udma_prep_slave_sg_pkt(uc, sgl, sglen, dir, tx_flags, context);